In the production of knitted goods the original knit product is normally a tube that is detwisted as described in copending application 134,268 filed Mar. 26, 1980 and is then longitudinally slit. It is then necessary to flatten out this slit tube in order that it can be dyed, treated with size or simply rolled up on a core.
Flattening out the slit tube is complicated considerably by the tendency of its edges to curl up. Accordingly, it is necessary to provide special devices which flatten out the slit tube to its proper width and which prevent its edges from curling back. This is normally achieved by passing the slit tube sinusoidally over a pair of so-called spreader rollers, each of which is subdivided at its center into a pair of screwthread formations of opposite hand. These rollers are rotated at a peripheral speed greater than the feed rate of the textile over them so that the screwthread formations exert an outward force on the web which holds it relatively flat.
Such a system has the disadvantage that the workpiece invariably wanders transverse to its feed direction back and forth on the spreader rollers. Equipment must be provided downstream of these rollers to properly position it in a direction transverse to the feed direction. The trouble with this arrangement is that if the goods are left unsupported for any distance the edges curl up again, making it extremely difficult to guide and center the web. This centering or guiding apparatus, even at its best, takes a relatively long portion of the feed path for the knit web.